1. Field of the Invention
The present invention is generally related to brakes for vehicles and more particularly to a push to release brake actuating assembly for a vehicle.
2. Description of Related Art
A push to release brake actuating assembly is one type of parking brake actuator that is used in a variety of vehicles. Other types of parking brake actuators include a hand brake actuator that is typically mounted toward the center of the vehicle so that the operator of the vehicle may set and release the brake with one hand. This type of brake actuator typically includes a lever that is pulled upward by the operator to set the parking brake. A push button is typically disposed at a distal end of the lever and is pushed by the operator to disengage a locking pawl and allow the lever to be moved to disengage the parking brake.
Another type of parking brake actuator is mounted near the floor of the vehicle and includes a pedal that is designed to be engaged by the operator's foot when the operator decides to set the parking brake. A release handle is typically mounted above the pedal. This handle allows the operator to disengage the parking brake by pulling the release handle, which disengages a locking pawl to free the arm on which the pedal is mounted for movement in the brake releasing direction. Some vehicles that have this type of parking brake actuator also have an automatic parking brake release that includes a vacuum motor or servo that is operatively connected to the locking pawl. When the vehicle is running and the transmission is shifted into gear, a solenoid valve is actuated. The solenoid valve causes vacuum to be applied to the vacuum motor, which causes the locking pawl to release from the pedal arm, thereby moving the pedal in the brake releasing direction.
A push to release type brake actuator is also mounted near the floor of the vehicle and includes a pedal that is designed to be engaged by the operator's foot when the operator decides to set the parking brake. The operator disengages the parking brake by pushing the pedal a second time, which frees the pedal for movement to its original position. Issues that have been encountered with the conventional push to release brake actuator include backlash and operational reliability. Backlash is the load drop that occurs when the operator releases the parking brake actuator and has been attributed to the design of some of the internal components of the brake actuator. Operational reliability depends on the robustness of the push to release operation, which depends on the accuracy of many of the internal component parts of the brake, as well as the accuracy of the finished assembly.
In an effort to increase and maintain a high level of operational reliability, very tight tolerances are used when manufacturing the brake actuator assembly. However, these tight tolerances tend to contribute to high backlash. Also, consistently achieving the tight tolerances also increase the cost to manufacture the brake actuator assembly.